Some types of vehicles installed with an engine automatic stop-and-restart system, such as an idle reduction control system, have been recently increasing for reduction in fuel cost, in exhaust emission, and the like. Such an idle reduction system installed in a vehicle is designed to shut off the supply of fuel to an internal combustion engine when, for example, the vehicle is temporarily stopped at a light or by a traffic jam, thus automatically stopping the internal combustion engine, referred to simply as “engine”.
After the stop of the engine, the idle reduction system is designed to automatically activate a starter in response to a driver's operation to restart the vehicle so that the starter cranks the engine, thus restarting it.
There are requirements to restart the engine during the vehicle coasting (being rotated without the aid of the engine) after the stop of the engine by the idle reduction system. In order to meet these requirements, starters are required for restart of the engine during the vehicle coasting in response to the driver's determination.
Conventional starters are normally designed to shift a pinion mounted on an output shaft of a motor to a ring gear of the engine concurrently with the movement of a movable contact of a switch to a stationary contact thereof for the electrical connection between the motor and a power supply unit in order to crank the engine.
Thus, in a vehicle integrated with such a conventional starter, if the conventional starter shifts the pinion to the ring gear of the engine concurrently with the movement of the movable contact of the switch to the stationary contact thereof during the vehicle coasting, it may be difficult for the pinion to be meshed with the ring gear due to the lack of the number of rotations of the motor, resulting in that the pinion may turn over without being engaged with the ring gear.
For this reason, these conventional starters are designed to shift the pinion to the ring gear of the engine so as to crank the engine after the rotation of the engine has been completely stopped.
Thus, in a vehicle integrated with such a conventional starter, after the vehicle has been temporally stopped at a red light so that the engine has been stopped, even if the red light is changed to green, the conventional starter cannot restart the engine immediately after the change of the red light to green so that the vehicle cannot be started immediately thereafter.
Accordingly, there are requirements to restart the engine in response to the driver's determination according to traffic conditions around the vehicle even if the vehicle is decelerated.
WO Patent Publication NO. 2007-101770-A1 discloses an example of techniques associated with a function capable of engaging the pinion with the ring gear of the engine during the vehicle being decelerated so as to restart the engine.
A starter disclosed in the WO Patent Publication is equipped with an electromagnetic actuator operative to shift a pinion mounted on an output shaft of a motor to a ring gear of an engine, and a switch operative to establish the electrical connection between the motor and a power supply unit and shut off the electrical connection therebetween. The starter is also equipped with a controller adapted to individually control the activation of the electromagnetic actuator and the actuation of the switch.
When an engine restart request occurs during the vehicle being decelerated after the stop of the engine, the starter designed set forth above controls the electromagnetic actuator to shift the pinion of the motor to the ring gear to be engaged therewith, and turns on the switch to rotate the motor, thus cranking the engine.